Hackaday Prize Entry: A One Hand Bottle Opener

For the next month, the Hackaday Prize is all about Assistive Technologies. You would think this means exoskeletons, 3D printed prosthetics, and better wheelchairs, and you’d be right. This project in the running for the Assistive Technologies portion of the prize isn’t what you would expect. It’s a brilliantly simple way to open a water bottle with one hand. Think of it as the minimum viable project for assistive technologies, and a brilliant use of a few 3D printed parts and some metric bolts.

The OHBO – the One Hand Bottle Opener – is just a simple 3D printed ring that fits over a water bottle. There’s a small arm attached with a few bolts that lock this ring onto the bottle. With this bottle opener attached, it only requires a simple twist of the wrist to open a screw-top bottle.

As you can see in the video below, this would be a fantastic device for anyone with one hand to keep around the fridge. Of course, like all good Hackaday Prize entries, all the files to recreate this build are available, with just a few bits of hardware required to complete the build.

I was going to comment to ‘use your teeth’ if you really have to…
But honesty, I’ve tried doing things ‘lefty only’ and if I lost my right hand I’m not sure I could deal with it. :/

It f***ing sucks, and that’s just imagining if I couldn’t use both hands; full sympathies to anyone who has had to (or does) deal with limited mobility. Honestly, I’ve seen a family member lose basically half of his body working.

To anyone who has to deal with this I wish the best. Great entry, even if it is relatively simple.

I was once left handed until one fateful day I was skateboarding at a DIY spot and had a bit of a massive accident. The short story is that I fell around 9 feet upside down and stiff armed the ground. I didn’t realize I had broken my arm/hand, picked up the board with that broken arm and walked over to a fence to sit down. A buddy said, “Look down, but don’t move”, sure enough I had 3 compound fractures sticking out of my forearm. Didn’t feel a thing.

Got a ride to the hospital and got the news that I had broken 7 bones in 14 places. Didn’t sound too bad to me from my experiences with breaking bones, I was already in the double digit club well before this news. After some plating and pinning, iron halo style fixture around my forearm and hand. A few casts and 9 months later. I’m finally liberated of mechanical isolation and can go about rehabbing my hand.

Well, it never really worked out the way I had hoped. I can’t rotate my wrist, can’t tilt it, can’t lift anything with it and could no longer write or paint with that hand ever again. I joke that it’s a decorative item and it’s just there as a place for my watch. I’m lucky to have what I got cause least it doesn’t interfere with my typing and buttons on jeans is no longer a real problem.

But I spent nearly a year being one handed. It sucks!

I’m serious about the button on jeans, back when I broke my good hand button fly jeans were the norm. Nearly soiling myself over stupid buttons!

Then there’s tying shoelaces one handed. At first I just gave up. I’d kick off the shoe with an untied lace and hand it to any person I could find and ask kindly, “Please do me a solid and tie this for me?” Eventually learned to tie a bow with one hand, admittedly it was a frustrating thing cause it’d always be a terrible knot and I’d get plenty of practice retying equally bad knots one handed.

So yeah, anything that helps can’t hurt.

Tho to pass on my own humble opinion in the hopes of being constructive. This seems a bit too fiddly to me. When I was living with my bad hand, opening a bottle wasn’t too much a struggle. Would hold it by the neck and spin it off with my thumb and index finger, hell I still do that now. Now if someone has other ailments affecting their motor functions, I feel that turning the screw bit is going to be troublesome. In my head it seems like something similar to an oil filter wrench might be a good solution.

I’m sorry to hear you had such a serious injury. I’ve done both wrists, an elbow, a shoulder (not at the same time!) and it sucks a lot to have an arm out of service. Sorry it’s happened to you.

You make a good point about the fiddly screw bit. Maybe pablopeza could work in some kind of multiple cam arrangement, so that as you twist it clamps up on the top. That would require a bit less messing around.

Hi Eric , sorry to hear about your injury … I hope you recover as best as possible. I am in a similar situation but less harmful. I have a trouble in the shoulder, and i had to stay one month using one arm only. This was the reason behind the proyect. It was a little hard to build the prototypes in my state, but i could and i hope that other people can do it, but is true, i need a way to improve it. I like the constructive critics like yours, because is the way to find problems and evolve it. I would like to develop a solution.
Greetings!

Maybe consider something not unlike the cam levers used on quick release bicycle wheels. You could still make it adjustable to fit various size caps… and by that I mean some brands’ bottle lids are considerably larger than the normal Coke / Pepsi lids, and also consider beer bottle and other such lids. Also consider where the bottle lacks a ring below the lid that would otherwise keep the device from sliding down the neck.

Most PET bottles have one of two cap designss.
There are already “cap decorations” that fit snugly and lock on tight, which are larger (think “it’s for little kids to learn how to use bottles”) and they work really well.
Until you come across that one drink product that has their own weird cap.

Anyway, just jam on and turn.. big fisted. No real manual dexterity required. Though you still need to somehow hold the bottle down.. like between your thighs or pressing down on a table.

So..a device that can be operated with one hand, grips a cylindrical object and will loosen a tightly threaded fitting. Ask any plumber/mechanic/disabled person – it’s called a strap wrench and they’re used for everything from threaded pipe to pickle jars. A small version could easily provide better leverage and less fiddly-ness.

A thumb sized version would be one-handed, as the original posted device is. The strap is usually sized approximately for the pipe/fitting, then rotation of the handle against the serrated “jaw” surface takes up the slack and provides leverage. There are also oil-filter wrenches that work the same way. I’ve used both one-handed.

It’s a nicely made solution, but it’s not exactly a problem it it?
Parents are always working one-handed with a kid in the other hand; these bottles are already easy enough to open one handed, except that you tend to drop the cap, which I don’t honk this device really stops either?

opening a bottle one handed is simple, except for the rare case of a really tight bottle.
1. Pick the bottle up by pinching the cap with your thumb and forefinger.
2. grip neck of bottle with other 3 fingers
3. twist with 2 fingers